At the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) in Long Island, New York, scientists study high-speed ion collisions that reveal what the universe may have looked like moments after the Big Bang. RHIC is the second-highest-energy heavy-ion collider in the world, after the Large Hadron Collider (LHC), and currently the only operating particle collider in the US.